A method of fabricating a solar cell for solar light power generation is as follows. First, after preparing a substrate, a back electrode layer is formed on the substrate and patterned by a laser, thereby forming a plurality of back electrodes.
Thereafter, a light absorbing layer, a buffer layer, and a high resistance buffer layer are sequentially formed on the back electrodes. Various schemes including a scheme of forming light absorbing layer by simultaneously or separately evaporating copper (Cu), indium (In), gallium (Ga), and selenium (Se) have been used in order to form the light absorbing layer.
Then, a buffer layer including cadmium sulfide (CdS) is formed on the light absorbing layer through a sputtering process. After that, a high resistance buffer layer including zinc oxide (ZnO) is formed on the buffer layer through the sputtering process. Subsequently, groove patterns may be formed on the light absorbing layer, the buffer layer, and the high resistance buffer layer.
Subsequently, a transparent conductive material is laminated on the high resistance buffer layer, and is filled in the groove pattern. Next, the groove pattern may be formed on the transparent electrode layer, so that a plurality of solar cells may be formed. The transparent electrodes and the back electrodes are misaligned with respect to each other, and electrically connected to each other through connection wires. Therefore, the solar cells may be electrically connected to each other in series.
As described above, in order to convert the solar light into electrical energy, various solar cell apparatuses have been fabricated for the use thereof. One of the solar cell apparatuses is disclosed in Korean Unexamined Patent Publication No. 10-2008-0088744.
Meanwhile, as foreign matters such as particles or second phases are formed in the process of depositing the light absorbing layer or dropped on the light absorbing layer after the light absorbing layer has been deposited, the buffer layer may not be smoothly deposited thereafter. Accordingly, a shunt circuit is made due to the short between the light absorbing layer and the front electrode layer, and efficiency is degraded.